An alternating coupling defrosting heat pump drying system

Abstract

The present invention discloses an alternating-coupling defrosting heat pump drying system, which relates to the technical field of processing. Aiming at the technical problems that when the existing heat pump drying system defrosts, the temperature in the drying room fluctuates greatly and the energy efficiency ratio of the heat pump drying system is relatively low, a solution for the alternating-coupling defrosting heat pump drying system is proposed. The alternating-coupling defrosting heat pump drying system includes a first subsystem and a second subsystem. The two subsystems are coupled by a heat recovery heat exchanger, and a defrosting throttle valve is respectively configured in each subsystem. The present invention realizes that when the defrosting function mode is carried out in winter, the compressor does not need to be shut down and the four-way valve does not need to be commutated. It not only maintains the stability of the temperature in the drying room, but also saves time, thereby improving the energy efficiency ratio of the defrosting heat pump drying system and reducing the energy consumption of the whole system.

Description

Technical Field

[0001] The present invention relates to the field of processing technologies, and particularly relates to an alternating coupled defrosting heat pump drying system. Background Art

[0002] In industrial and agricultural heat pump drying systems (heat pump drying units), the evaporator is prone to frosting under winter operating conditions. When performing the existing defrosting function mode, the compressor in the heat pump drying system needs to perform processes such as shutdown and four-way valve commutation. However, this processing process will have a greater impact on the energy efficiency ratio of the entire heat pump drying system, and it is easy to cause large fluctuations in the temperature in the drying room, thereby affecting the energy efficiency of the entire heat pump drying system. Summary of the Invention

[0003] An alternating coupled defrosting heat pump drying system proposed by the present invention solves the technical problem that when the existing heat pump drying system performs the defrosting function mode, the temperature in the drying room is prone to large fluctuations, resulting in a relatively low energy efficiency ratio of the heat pump drying system.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An alternating coupled defrosting heat pump drying system includes a first subsystem and a second subsystem. The first subsystem includes a first compressor and a first condenser. The exhaust end of the first compressor is connected to the input end of the first condenser. The output end of the first condenser away from the first compressor is connected to a first defrosting throttle valve. The outlet end of the first defrosting throttle valve away from the first condenser is connected to a heat recovery heat exchanger. The output end of the heat recovery heat exchanger away from the first defrosting throttle valve is connected to a first main throttle valve. The output end of the first main throttle valve away from the heat recovery heat exchanger is connected to a first evaporator. The output end of the first evaporator away from the first main throttle valve is connected to the input end of the first compressor. The first compressor, the first condenser, the first defrosting throttle valve, the heat recovery heat exchanger, the first main throttle valve, and the first evaporator are sequentially connected through copper pipes;

[0006] The second subsystem includes a second compressor and a second condenser. The exhaust end of the second compressor is connected to the input end of the second condenser. The output end of the second condenser, which is far from the second compressor, is connected to a second defrosting throttle valve. The outlet end of the second defrosting throttle valve, which is far from the second condenser, is connected to a heat recovery heat exchanger. The output end of the heat recovery heat exchanger, which is far from the second defrosting throttle valve, is connected to a second main throttle valve. The output end of the second main throttle valve, which is far from the heat recovery heat exchanger, is connected to a second evaporator. The output end of the second evaporator, which is far from the second main throttle valve, is connected to the input end of the second compressor. The second compressor, the second condenser, the second defrosting throttle valve, the heat recovery heat exchanger, the second main throttle valve, and the second evaporator are sequentially connected through copper pipes. The first subsystem and the second subsystem are connected through the heat recovery heat exchanger.

[0007] Preferably, a first evaporator fan is arranged on one side of the first evaporator, and a first condenser fan is arranged on one side of the first condenser;

[0008] A second evaporator fan is arranged on one side of the second evaporator, and a second condenser fan is arranged on one side of the second condenser.

[0009] Preferably, the alternating coupled defrosting heat pump drying system further includes a first defrosting circuit and a second defrosting circuit. The first defrosting circuit is formed by the first compressor passing through the first condenser, the first defrosting throttle valve, the heat recovery heat exchanger, the first main throttle valve, and the first evaporator in sequence and then returning to the first compressor;

[0010] The second defrosting circuit is formed by the second compressor passing through the second condenser, the second defrosting throttle valve, the heat recovery heat exchanger, the second main throttle valve, and the second evaporator in sequence and then returning to the second compressor.

[0011] Preferably, the alternating coupled defrosting heat pump drying system has the following two circuit states:

[0012] (Ⅰ) The circuit state when the alternating coupled defrosting heat pump drying system performs the conventional drying function on the drying room. At this time, a first conventional drying circuit and a second conventional drying circuit are respectively formed in the first subsystem and the second subsystem. Among them, the first conventional drying circuit is formed by the first compressor passing through the first condenser, the first defrosting throttle valve, the heat recovery heat exchanger, the first main throttle valve, and the first evaporator in sequence and then returning to the first compressor. Among them, the first defrosting throttle valve is in the fully open state; the second conventional drying circuit is formed by the second compressor passing through the second condenser, the second defrosting throttle valve, the heat recovery heat exchanger, the second main throttle valve, and the second evaporator in sequence and then returning to the second compressor. Among them, the second defrosting throttle valve is in the fully open state;

[0013] (II) Circuit state when the alternating coupled defrosting heat pump drying system performs the defrosting function. Among them, (a) When the first subsystem performs the defrosting function, a first defrosting circuit is formed at this time. The first defrosting circuit goes from the first compressor through the first condenser, the first defrosting throttle valve, the heat recovery heat exchanger, the first main throttle valve, and the first evaporator in sequence and then returns to the first compressor. At this time, the first main throttle valve is in the fully open state, and the first condenser fan and the first evaporator fan are in the closed state. The second subsystem is in the normal drying state for the drying room;

[0014] (b) When the second subsystem performs the defrosting function, a second defrosting circuit is formed at this time. The second defrosting circuit goes from the second compressor through the second condenser, the second defrosting throttle valve, the heat recovery heat exchanger, the second main throttle valve, and the second evaporator in sequence and then returns to the second compressor. At this time, the second main throttle valve is in the fully open state, and the second condenser fan and the second evaporator fan are in the closed state. The first subsystem is in the normal drying state for the drying room.

[0015] Compared with the existing technology, the beneficial effects of the present invention are:

[0016] By setting two alternately coupled defrosting heat pump drying subsystems, the present invention realizes that when the defrosting heat pump drying system is in the defrosting function mode in winter, the compressor does not need to be shut down and the four-way valve does not need to be commutated. This not only maintains the stability of the temperature in the drying room, but also saves the time spent on shutting down the compressor and commutating the four-way valve in the existing heat pump drying system during the normal defrosting function mode. Furthermore, it improves the energy efficiency ratio of the defrosting heat pump drying system and reduces the energy consumption of the entire system. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of an alternating coupled defrosting heat pump drying system proposed by the present invention.

[0018] In the figure: 3. First condenser; 4. First compressor; 6. First evaporator; 7. First main throttle valve; 8. First condenser fan; 9. First evaporator fan; 10. First defrosting throttle valve; 12. Heat recovery heat exchanger; 23. Second condenser; 24. Second compressor; 26. Second evaporator; 27. Second main throttle valve; 28. Second condenser fan; 29. Second evaporator fan; 20. Second defrosting throttle valve. Detailed Embodiment

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0020] Refer to Figure 1, an alternating-coupled defrosting heat pump drying system, comprising a first subsystem and a second subsystem. The first subsystem includes a first compressor 4 and a first condenser 3. The exhaust end of the first compressor 4 is connected to the input end of the first condenser 3. The output end of the first condenser 3 away from the first compressor 4 is connected to a first defrosting throttle valve 10. The outlet end of the first defrosting throttle valve 10 away from the first condenser 3 is connected to a heat recovery heat exchanger 12. The output end of the heat recovery heat exchanger 12 away from the first defrosting throttle valve 10 is connected to a first main throttle valve 7. The output end of the first main throttle valve 7 away from the heat recovery heat exchanger 12 is connected to a first evaporator 6. The output end of the first evaporator 6 away from the first main throttle valve 7 is connected to the input end of the first compressor 4. The first compressor 4, the first condenser 3, the first defrosting throttle valve 10, the heat recovery heat exchanger 12, the first main throttle valve 7, and the first evaporator 6 are sequentially connected through copper pipes;

[0021] The second subsystem includes a second compressor 24 and a second condenser 23. The exhaust end of the second compressor 24 is connected to the input end of the second condenser 23. The output end of the second condenser 23 away from the second compressor 24 is connected to a second defrosting throttle valve 20. The outlet end of the second defrosting throttle valve 20 away from the second condenser 23 is connected to a heat recovery heat exchanger 12. The output end of the heat recovery heat exchanger 12 away from the second defrosting throttle valve 20 is connected to a second main throttle valve 27. The output end of the second main throttle valve 27 away from the heat recovery heat exchanger 12 is connected to a second evaporator 26. The output end of the second evaporator 26 away from the second main throttle valve 27 is connected to the input end of the second compressor 24. The second compressor 24, the second condenser 23, the second defrosting throttle valve 20, the heat recovery heat exchanger 12, the second main throttle valve 27, and the second evaporator 26 are sequentially connected through copper pipes. The first subsystem and the second subsystem are connected through the heat recovery heat exchanger 12.

[0022] In this embodiment, a first evaporator fan 9 is provided on one side of the first evaporator 6, and a first condenser fan 8 is provided on one side of the first condenser 3;

[0023] A second evaporator fan 29 is provided on one side of the second evaporator 26, and a second condenser fan 28 is provided on one side of the second condenser 23.

[0024] In this embodiment, the defrosting heat pump drying system further includes a first defrosting circuit and a second defrosting circuit. The first defrosting circuit is that the first compressor 4 sequentially passes through the first condenser 3, the first defrosting throttle valve 10, the heat recovery heat exchanger 12, the first main throttle valve 7, and the first evaporator 6 and then returns to the first compressor 4;

[0025] The second defrosting circuit is that the second compressor 24 sequentially passes through the second condenser 23, the second defrosting throttle valve 20, the heat recovery heat exchanger 12, the second main throttle valve 27, and the second evaporator 26 and then returns to the second compressor 24.

[0026] In this embodiment, first, the alternating-coupled defrosting heat pump drying system of the present invention performs a conventional drying function on the drying chamber: by opening the first main throttle valve 7 and the second main throttle valve 27, fully opening the first defrosting throttle valve 10 and the second defrosting throttle valve 20, at this time, a first conventional drying circuit and a second conventional drying circuit are respectively formed in the first subsystem and the second subsystem. Among them, in the first conventional drying circuit, hot air starts from the first compressor 4, and sequentially passes through the first condenser 3, the heat recovery heat exchanger 12, the first main throttle valve 7, and the first evaporator 6 through a copper pipe and then returns to the first compressor 4; in the second conventional drying circuit, hot air starts from the second compressor 24, and sequentially passes through the second condenser 23, the heat recovery heat exchanger 12, the second main throttle valve 27, and the second evaporator 26 through a copper pipe and then returns to the second compressor 24;

[0027] Then, make the above-mentioned alternating-coupled defrosting heat pump drying system enter the preparation stage before the defrosting function: by gradually reducing the valves of the first main throttle valve 7 and the second main throttle valve 27, the refrigerant storage amounts in the first evaporator 6 and the second evaporator 26 are gradually reduced;

[0028] Next, make the above-mentioned alternating-coupled defrosting heat pump drying system perform the defrosting function:

[0029] When the first subsystem performs the defrosting function: by opening the first defrosting throttle valve 10, closing the first condenser fan 8 and the first evaporator fan 9, increasing the input power of the first compressor 4, and at the same time fully opening the first main throttle valve 7, at this time, a first defrosting circuit is formed in the first subsystem. The first defrosting circuit is that the first compressor 4 sequentially passes through the first condenser 3, the first defrosting throttle valve 10, the heat recovery heat exchanger 12, the first main throttle valve 7, and the first evaporator 6 and then returns to the first compressor 4. At this time, the first evaporator 6 is thermally defrosted by absorbing the heat in the second subsystem through the heat recovery heat exchanger 12, and at this time, the second subsystem still performs the conventional drying function on the drying chamber, so that the overall temperature fluctuation in the drying chamber is relatively small during the switching to the defrosting function;

[0030] (Ⅱ) When the second subsystem performs the defrosting function: By opening the second defrost throttle valve 20, closing the second condenser fan 28 and the second evaporator fan 29, increasing the input power of the second compressor 24, and fully opening the second main throttle valve 27, a second defrosting circuit is formed in the second subsystem. This second defrosting circuit consists of the second compressor 24 successively passing through the second condenser 23, the second defrost throttle valve 20, the heat recovery heat exchanger 12, the second main throttle valve 27, and the second evaporator 26 and then returning to the second compressor 24. At this time, the heat in the first subsystem is absorbed to perform heat defrosting on the second evaporator 26, while the first subsystem resumes the normal drying function for the drying room, thereby enabling the defrosting heat pump drying system to complete the defrosting process without shutting down, improving the energy efficiency ratio of the defrosting heat pump drying system, and being more energy-efficient and efficient than the existing defrosting heat pump drying systems.

[0031] The above is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered by the protection scope of the present invention.

Claims

1. An alternating-coupled defrosting heat pump drying system, comprising a first subsystem and a second subsystem, characterized in that, the first subsystem includes a first compressor (4) and a first condenser (3), the exhaust end of the first compressor (4) is connected to the input end of the first condenser (3), the output end of the first condenser (3) far away from the first compressor (4) is connected with a first defrosting throttle valve (10), the outlet end of the first defrosting throttle valve (10) far away from the first condenser (3) is connected with a heat recovery heat exchanger (12), the output end of the heat recovery heat exchanger (12) far away from the first defrosting throttle valve (10) is connected with a first main throttle valve (7), the output end of the first main throttle valve (7) far away from the heat recovery heat exchanger (12) is connected with a first evaporator (6), the output end of the first evaporator (6) far away from the first main throttle valve (7) is connected to the input end of the first compressor (4), and the first compressor (4), the first condenser (3), the first defrosting throttle valve (10), the heat recovery heat exchanger (12), the first main throttle valve (7) and the first evaporator (6) are sequentially connected through copper pipes; the second subsystem includes a second compressor (24) and a second condenser (23), the exhaust end of the second compressor (24) is connected to the input end of the second condenser (23), the output end of the second condenser (23) far away from the second compressor (24) is connected with a second defrosting throttle valve (20), the outlet end of the second defrosting throttle valve (20) far away from the second condenser (23) is connected with a heat recovery heat exchanger (12), the output end of the heat recovery heat exchanger (12) far away from the second defrosting throttle valve (20) is connected with a second main throttle valve (27), the output end of the second main throttle valve (27) far away from the heat recovery heat exchanger (12) is connected with a second evaporator (26), the output end of the second evaporator (26) far away from the second main throttle valve (27) is connected to the input end of the second compressor (24), and the second compressor (24), the second condenser (23), the second defrosting throttle valve (20), the heat recovery heat exchanger (12), the second main throttle valve (27) and the second evaporator (26) are sequentially connected through copper pipes, and the first subsystem and the second subsystem are connected through the heat recovery heat exchanger (12).

2. The alternating-coupled defrosting heat pump drying system according to claim 1, characterized in that, a first evaporator fan (9) is arranged on one side of the first evaporator (6), and a first condenser fan (8) is arranged on one side of the first condenser (3); a second evaporator fan (29) is arranged on one side of the second evaporator (26), and a second condenser fan (28) is arranged on one side of the second condenser (23).

3. The alternating-coupled defrosting heat pump drying system according to claim 1 or 2, characterized in that, The alternating coupled defrosting heat pump drying system further includes a first defrosting circuit and a second defrosting circuit. The first defrosting circuit is formed by a first compressor (4) sequentially passing through a first condenser (3), a first defrosting throttle valve (10), a heat recovery heat exchanger (12), a first main throttle valve (7), and a first evaporator (6) and then returning to the first compressor (4). The second defrosting circuit is formed by a second compressor (24) sequentially passing through a second condenser (23), a second defrosting throttle valve (20), a heat recovery heat exchanger (12), a second main throttle valve (27), and a second evaporator (26) and then returning to the second compressor (24).

4. An alternating coupled defrosting heat pump drying system according to claim 2, characterized in that the alternating coupled defrosting heat pump drying system has the following two circuit states: (Ⅰ) The circuit state when the alternating coupled defrosting heat pump drying system performs a conventional drying function on the drying chamber. At this time, a first conventional drying circuit and a second conventional drying circuit are respectively formed in the first subsystem and the second subsystem. Among them, the first conventional drying circuit is formed by a first compressor (4) sequentially passing through a first condenser (3), a first defrosting throttle valve (10), a heat recovery heat exchanger (12), a first main throttle valve (7), and a first evaporator (6) and then returning to the first compressor (4). At this time, the first defrosting throttle valve (10) is in a fully open state; the second conventional drying circuit is formed by a second compressor (24) sequentially passing through a second condenser (23), a second defrosting throttle valve (20), a heat recovery heat exchanger (12), a second main throttle valve (27), and a second evaporator (26) and then returning to the second compressor (24). At this time, the second defrosting throttle valve (20) is in a fully open state; (Ⅱ) The circuit state when the alternating coupled defrosting heat pump drying system performs a defrosting function. Among them, (a) when the first subsystem performs a defrosting function, a first defrosting circuit is formed at this time. The first defrosting circuit is formed by a first compressor (4) sequentially passing through a first condenser (3), a first defrosting throttle valve (10), a heat recovery heat exchanger (12), a first main throttle valve (7), and a first evaporator (6) and then returning to the first compressor (4). At this time, the first main throttle valve (7) is in a fully open state, the first condenser fan (8) and the first evaporator fan (9) are in a closed state, and the second subsystem is in a conventional drying state for the drying chamber; (b) When the second subsystem performs a defrosting function, a second defrosting circuit is formed at this time. The second defrosting circuit is formed by a second compressor (24) sequentially passing through a second condenser (23), a second defrosting throttle valve (20), a heat recovery heat exchanger (12), a second main throttle valve (27), and a second evaporator (26) and then returning to the second compressor (24). At this time, the second main throttle valve (27) is in a fully open state, the second condenser fan (28) and the second evaporator fan (29) are in a closed state, and the first subsystem is in a conventional drying state for the drying chamber.

Images